extendible and retractable dog
flexible retractable roof
integrally retractable alternative cutting element
retractable actuation mechanism
retractable core barrel
Retractable counterweight
retractable locking arm
retractable main girder
Retractable Roof
开合屋顶
开闭屋盖
活动屋盖
开合屋盖
开启屋盖
可移动车顶
Retractable Roof Structure